Next Article in Journal
Phosphoprotein Phosphatase 1 but Not 2A Activity Modulates Coupled-Clock Mechanisms to Impact on Intrinsic Automaticity of Sinoatrial Nodal Pacemaker Cells
Next Article in Special Issue
Influence of Light of Different Spectral Compositions on the Growth, Photosynthesis, and Expression of Light-Dependent Genes of Scots Pine Seedlings
Previous Article in Journal
NK Cell Regulation in Cervical Cancer and Strategies for Immunotherapy
Previous Article in Special Issue
Identification of a Novel Mutation Exacerbated the PSI Photoinhibition in pgr5/pgrl1 Mutants; Caution for Overestimation of the Phenotypes in Arabidopsis pgr5-1 Mutant
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Cells
Volume 10
Issue 11
10.3390/cells10113105
cells-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

The Combined Effect of ZnO and CeO2 Nanoparticles on Pisum sativum L.: A Photosynthesis and Nutrients Uptake Study

by
Elżbieta Skiba
1,*,
Monika Pietrzak
1,
Sława Glińska
2 and
Wojciech M. Wolf
1
1
Institute of General and Ecological Chemistry, Lodz University of Technology, 90-924 Lodz, Poland
2
Laboratory of Microscopic Imaging and Specialized Biological Techniques, Faculty of Biology and Environmental Protection, University of Lodz, 90-237 Lodz, Poland
*
Author to whom correspondence should be addressed.
Cells 2021, 10(11), 3105; https://doi.org/10.3390/cells10113105
Submission received: 20 September 2021 / Revised: 3 November 2021 / Accepted: 5 November 2021 / Published: 10 November 2021
(This article belongs to the Special Issue Photosynthesis under Biotic and Abiotic Environmental Stress)
Browse Figures
Versions Notes

Abstract

:
Cerium oxide nanoparticles (CeO2 NPs) and zinc oxide nanoparticles (ZnO NPs) are emerging pollutants that are likely to occur in the contemporary environment. So far, their combined effects on terrestrial plants have not been thoroughly investigated. Obviously, this subject is a challenge for modern ecotoxicology. In this study, Pisum sativum L. plants were exposed to either CeO2 NPs or ZnO NPs alone, or mixtures of these nano-oxides (at two concentrations: 100 and 200 mg/L). The plants were cultivated in hydroponic system for twelve days. The combined effect of NPs was proved by 1D ANOVA augmented by Tukey’s post hoc test at p = 0.95. It affected all major plant growth and photosynthesis parameters. Additionally, HR-CS AAS and ICP-OES were used to determine concentrations of Cu, Mn, Fe, Mg, Ca, K, Zn, and Ce in roots and shoots. Treatment of the pea plants with the NPs, either alone or in combination affected the homeostasis of these metals in the plants. CeO2 NPs stimulated the photosynthesis rate, while ZnO NPs prompted stomatal and biochemical limitations. In the mixed ZnO and CeO2 treatments, the latter effects were decreased by CeO2 NPs. These results indicate that free radicals scavenging properties of CeO2 NPs mitigate the toxicity symptoms induced in the plants by ZnO NPs.

Graphical Abstract

1. Introduction

Nowadays, synthetic nanomaterials (NMs) are finding applications in almost all material aspects of human life and are particularly vital for contemporary technology and medicine [1,2,3,4,5]. The most important are sustainable energy production and storage, electronic devices, catalysts, sensors and adhesives, high-quality petro- and agrochemicals [6,7,8,9,10,11,12,13,14]. Their widespread use raises fundamental questions related to the environment, pollution, and safety [15,16,17].
In the diverse world of nanomaterials metal oxides firmly occupy a unique position. Their global market in 2020 was worth almost USD 5.3 billion with several forecasts indicating its steady rise to USD 9.3 billion in 2027 [18]. Obviously, this growing stream of NMs cannot be completely isolated from soil, air, or water and finally will find its way to terrestrial living organisms. Therefore, complex interactions of nanoparticles (NPs) with the biota and their further environmental fate deserve additional studies.
In a number of comprehensive papers on interactions of nanoparticles with living organisms, the authors investigated the role of chemical composition, particle shape, size, and mechanisms of aggregation of NPs [19,20,21,22]. The beneficial or harmful effects of NPs were also examined. Owing to their unique properties, nanomaterials can be successfully used in fertilizers, pesticides, or as dedicated chemical carriers or sensors [23,24,25]. This increasing flux of diverse nanomaterials approaching soil and plant environments should not be left without comprehensive studies on their migrations, uptake, and toxicities. The emerging picture suggests dynamic processes which act in complicated matrices. Identification of interactions among various substances poses a real challenge.
Obviously, nanoparticles affect plant metabolism in a number of ways and finally introduce changes to plant physiology at cellular, organ, and individual plant levels [26,27,28,29]. In particular, photosynthesis—the essential, bioenergy-generating process [30]—may be either facilitated or hampered by nanoparticles [31,32,33,34,35,36]. As pointed out by Du et al. [37] and Tighe-Neira et al. [35], the latter may be conveniently examined by gas exchange parameters augmented with the contents of photosynthetic pigments. Unfortunately, results are rarely completely consistent and a wide range of plant responses to nanoparticles could be expected. Notably, metal oxide NPs usually alter the photosynthesis rate, photochemical fluorescence, and quantum yield in plants [37] with ZnO and CeO2 being among the most active. Mukherjee et al. [38] described the negative effect of ZnO NPs at soil concentrations 125–500 mg/L on chlorophyll activity in Pisum sativum L. It results from the substitution of the Mg atoms at chlorophyll centers by Zn which finally hampers the photosynthesis process. The opposite effect was observed by Reddy Pullagurala et al. [39] during cilantro (Coriandrum sativum) cultivation. Supplementation with 100 or 200 mg/L ZnO NPs induced photosynthetic pigments production and boosted photosynthesis.
The ambient character of nanoparticulate cerium oxide combined with its increasing abundance in the environment makes this substance a useful agent to study plant metabolism effects triggered by anthropogenic nanomaterials. In particular, Wu et al. [32] demonstrated that CeO2 NPs (nanoceria) are a reactive oxygen species (ROS) scavenger in leaf mesophyll cells and defend the chloroplast photosynthetic machinery from abiotic stresses. On the other hand, the negative effect of nanoceria on photosynthesis in soybean plants was investigated by Li et al. [40]. They pointed out several aspects which are at stake, namely: inhibited conversion efficiency of C5 to C3 in the Calvin–Benson cycle, destruction of thylakoid membranes, and reduced chlorophyll synthesis and activity. All these factors participate in the final plant destruction.
Regrettably, the most relevant works on the subject are aimed at particular types of nanoparticles. Investigations of combined, mutual effects induced by either mixture of NPs or their additives and stabilizers are quite scarce. In real ecosystems, nanoparticles rarely play a solo performance, which is especially important in modern efficient agriculture. Increasing pressure on massive food production for the rapidly growing population has prompted the development of new, smart, and efficient agrochemicals [41,42,43,44].
The fertilizing effect of CeO2 and ZnO NPs attracted the attention of several research groups. It is quite well documented that cerium oxide NPs can alleviate plant salinity stress, act as a catalyst in chlorophyll production, and in scavenging reactive oxygen species which stabilize the chloroplast structure and cell walls [45,46,47]. On the other hand, nanoparticulate zinc oxide may be used to counteract cadmium toxicity in wheat and elevate zinc concentrations in plants. Thus, it can be a useful agent for Zn biofortification in cereals plantations and help to overcome the well recognized hidden hunger in humans resulting from the deficiency of Zn in cereals [25]. In this respect, optimization of photosynthetic efficiency by nanoparticles is a highly promising approach for a smart increase of crop production [48].
Mixtures of nanoparticles that are present in the growth environment affect plant development in a different way than single species [49,50,51]. In particular, the combined, mutual interactions between ZnO and CeO2 are quite likely indeed. Both substances often coexist in all compartments of the environment and their simultaneous presence in the environment is more than likely. Our previous works on Pisum sativum L. were related to metal migration strategies as induced by single stressors such as CeO2 or ZnO nanoparticles [52,53]. We have shown that zinc species alter Cu, Mn, and Fe uptake and their further migration in green pea. On the other hand, low concentrations of cerium oxide NPs increased the photosynthesis rate. Those investigations had a model character and did not account for combined effects as triggered by ZnO and CeO2 together in real plant matrices. This study enhances this approach significantly. Here, we examine the mixture of nanometric cerium and zinc oxides. The methodology has been based on hydroponic pot experiments [54]. Pea is frequently applied in system biology experiments and is treated as a non-model plant with a roughly complete genome structure [55,56]. It is cultivated worldwide [57] and additive interactions which affect nutrient uptake and enhance plant growth yield are of practical relevance.

2. Materials and Methods

2.1. Nanoparticles Characteristic

CeO2 NPs and ZnO NPs were purchased from the Byk (Byk-Chemie GmbH, Wesel, Germany) as commercially available products. The properties of nanoparticles, including average particle size, transmission electron microscopy (TEM) images, and zeta potential are given in Table S1 [52,54].

2.2. Plants Growth Conditions and Treatments

Pisum sativum L. plants were cultivated under hydroponic conditions in Hoagland’s nutrient solution. The composition of the growing medium and the detailed setup of the experiment were described previously [53,54]. The seeds, (“Iłówiecki” sugar pea, “PNOS” Co., Ltd., Ożarów Mazowiecki, Poland), sterilized in 70% ethanol were germinated in dark for 3 days. Next, the seedlings (at BBCH 09 phenological stage [58]) were transferred to perforated plastic plates and placed in containers with the nutrient solution. Each growing vessel contained 26 pea seedlings. Pisum sativum L. was grown in Hoagland’s nutrient solution for 4 days in a controlled environment: light of 170 µmol/m2 intensity, average temperature 21 ± 3 °C, and 16/8 h day/night photoperiod. On the 5th day, the nutrient solutions were supplemented with nanoparticles. The treatments were as follows, CeO2 NPs: 100 mg (Ce)/L; CeO2 NPs: 200 mg (Ce)/L; ZnO NPs: 100 mg (Zn)/L; ZnO NPs: 200 mg (Zn)/L; two mixtures of CeO2 and ZnO NPs: 100 mg (Ce)/L + 100 mg (Zn)/L and 200 mg (Ce)/L + 200 mg (Zn)/L. Plants grown in Hoagland’s nutrient solution served as the control group. In each variant of the experiment, six growing vessels were used. Fresh liquid media were supplied every 48 h. Pisum sativum L. was harvested after 12 days of exposure when plants reached the BBCH 15 phenological stage.

2.3. Growth Parameters

Root and stem lengths were measured at the end of cultivation (Figure 1). Next, the roots were thoroughly rinsed with deionized water and separated from the shoots. The fresh weight of roots and shoots was measured and calculated per single plant (mg/plant). Prior to the chemical analysis, the collected fresh plants material was dried to a constant weight at 55 °C.

2.4. Elements Content

The dried samples of roots and shoots were digested in the mixture of concentrated HNO3 and HCl (6:1, v/v) using a Multiwave 3000 Anton Paar microwave reaction system (Anton Paar GmbH, Graz, Austria). The concentrations of Cu, Mn, Zn, Fe, and Mg were determined by a High-Resolution Continuum Source Atomic Absorption spectrometer HR-CS AAS (contrAA300, Analytik Jena, Jena, Germany). Additionally, the digested solutions were analyzed for Ce, Ca, and K concentrations by an Inductively Coupled Plasma–Optical Emission spectrometer ICP-OES (PlasmaQuant PQ 9000, Analytik Jena, Jena, Germany). Certified reference material of plant leaves of Oriental Basma Tobacco Leaves (INCT-OBTL-5) obtained from the Institute of Nuclear Chemistry and Technology, Warsaw [59] was used to check the reliability of the applied analytical procedures. Recoveries ranging from 96% to 108% were obtained. The detailed numerical data are given in Table S2.

2.5. Tolerance Index (TI) and Translocation Factor (TF)

Tolerance indices (TI) and translocation factors (TF) were calculated for plants treated with nanoparticulate oxides. TI is defined as the ratio between the root length of treated plants and that of plants in the control group [60,61]. The effectiveness of metal translocation from roots to shoots was assessed using TF, defined as the ratio of average element content in shoots to that in roots [62,63].

2.6. Photosynthetic Pigments

Contents of photosynthetic pigments, i.e., chlorophyll a and b and carotenoids in Pisum sativum L. leaves were determined following the method developed by Oren et al. [64]. All pigments were extracted from leaves with 80% acetone and kept in the dark at 4 °C. The absorbance of extracts was measured at wavelengths 470, 646, and 663 nm by SpectraMaxi3x (Molecular Devices, San Jose, CA, USA) on samples centrifugated at 4000 rpm for 10 min. Contents of pigments were calculated by the formula proposed by Lichtenthaler and Wellburn [65]. For comparison, the nondestructive measurements of relative chlorophyll content in fully expanded leaves at the fourth node were performed by the Soil Plant Analysis Development SPAD-502Plus chlorophyll meter (Konica–Minolta, Inc., Osaka, Japan).

2.7. Photosynthetic Parameters

Photosynthetic parameters, such as: leaf net photosynthesis (A), sub-stomatal CO2 concentration (Ci), transpiration (E), stomatal conductance (gs), photosynthetic water use efficiency (WUE), and photosynthetic CO2 response curve (A/Ci) were determined with a portable gas exchange analyzer (CIRAS-3; PP Systems, Amesbury, MA, USA). Measurements were performed 12 days after the administration of nanoparticles on fully expanded leaves at the fourth node. PARi levels at 1000 µmol/m2s were obtained from an LED Light Unit (RGBW) connected to the gas analyzer. The temperature within the chamber was kept at 25 °C, relative humidity at 80%, and reference CO2 concentration at 390 µmol/mol. Photosynthetic CO2 response curves were collected at a CO2 concentration gradient ranging from 0 to 1500 µmol/mol. All measurements were performed on fully expanded leaves at the fourth node. The acclimatization time between measurements was 120 s. The results from each CO2 level were recorded three times. Two biochemical parameters: maximum carboxylation rate (Vcmax) and maximum electron transport rate (Jmax) were calculated in Rstudio (v.3.4.2; R Foundation for Statistical Computing, Vienna, Austria) [66] using the “plantecophys” package developed by Duursma [67].

2.8. Statistical Analysis

All treatments were replicated six times, numerical results are accompanied by their ± SD (standard deviation). Statistical analysis was performed with the OriginPro 2016 (OriginLab Corporation, Northampton, MA, USA) software. The normality of the sample distributions was proved by the Shapiro–Wilk test [68]. The initial hypothesis on equal variances of investigated populations was validated with the Bartlett test [69]. A one-way ANOVA with Tukey’s post hoc approach was applied to validate differences between means. The probability level p = 0.95 was applied.

3. Results and Discussion

3.1. Growth Parameters

Several plant growth parameters were determined after twelve days of exposure time to illustrate the pea plant behavior under the combined treatments of nanoparticulate CeO2 and ZnO. Roots and stem lengths and their fresh weights are shown in Figure 1.
Almost all supplementations decreased roots length of pea as compared to the control treatment. Nevertheless, this effect is less pronounced for plants cultivated with the addition of ZnO (100 and 200 mg/L) than for the CeO2 (100 and 200 mg/L) treatments. It is directly correlated with the nanoparticles concentration applied. Notably, supplementation with mixed NPs resulted in roots shortening similar to that observed for relevant sole nanoceria concentrations. The order of tolerance indices (TI) supports above observations: (Zn 100) ≈ (Zn 200) > (Ce 100 + Zn 100) ≈ (Ce 100) > (Ce 200 + Zn 200) ≈ (Ce 200). Numbers in brackets represent supplementations of nanoparticles given in mg/L of elemental cerium or zinc, numerical values are presented in Table S3. Stem elongation was triggered by (Ce 100) and (Ce 200). A reverse effect was observed for (Zn 200) and (Ce 200 + Zn 200) administrations. Notably, the majority of treatments left the root mass unchanged with (Ce 100) and (Ce 200 + Zn 200) being the chief exceptions (Figure 1b). The biomass of the above-ground parts decreased upon all supplementations. The only exception was (Ce 100) with a biomass similar to that of a control sample.

3.2. Cerium and Zinc Concentrations

Cerium and zinc concentrations in roots and shoots along with their translocation factors are summarized in Table 1. The highest cerium content was determined for (Ce 200) treatment while the lowest levels were observed for combined (Ce 100 + Zn 100) and (Ce 200 + Zn 200) administrations. Respective translocation factors were remarkably low, which indicates that plants accumulate cerium primarily in roots. Cerium was not detected in plants grown in Hoagland’s nutrient solutions which were not supplemented with this element. Zinc is an essential element necessary for proper plant development [70,71]. The amounts of zinc accumulated by pea cultivated in solutions supplemented with the ZnO NPs alone were substantially larger than those observed for control samples. Combined treatments, namely (Ce 100 + Zn 100) and (Ce 200 + Zn 200) decreased Zn levels in both roots and shoots as compared to respective sole ZnO NPs administrations. However, all relevant concentrations highly exceeded critical toxic zinc level 300 mg/kg as suggested by Broadley et al. [70,71]. Similar to nanoceria administrations, the vast majority of zinc was immobilized in roots.

3.3. Photosynthetic Pigments

Measurements of photosynthetic pigments provide useful information on the physiological status of plants [72]. Concentrations of chlorophylls and carotenoids which are involved in the absorption and further transfer of light energy are prone to changes induced by inorganic chemical stressors [73]. Contents of chlorophyll a (Chl a), chlorophyll b (Chl b), and carotenoids (Car) in leaves of pea treated with nano-oxides are summarized in Figure 2a.
Significant differences among those parameters were observed. Almost all treatments prompted a decrease in photosynthetic pigments. The highest reduction was observed under (Zn 200) administration. Similar results were obtained by Hu et al. [74] who found that the lowest level of photosynthetic pigments in Salvinia natans grown in hydroponic conditions was reached in cultures supplemented with nanometric ZnO at 50 mg/L. Pea plants exposed to (Zn 100) and (Zn 200) showed initial symptoms of leaf chlorosis (Figure 2b). The chlorophyll loss associated with chlorosis is one of the typical symptoms of Zn excess in plants [75,76,77]. In this study, Zn levels in pea shoots under (Zn 100) and (Zn 200) administrations (Table 1) were significantly higher than the critical Zn toxicity level (>300 mg/kg) as quoted in the highly respected Marschner’s Mineral Nutrition of Higher Plants [71].
Moreover, the lowest Chl a, Chl b, and Car concentrations were observed for the sole (Zn 200) treatment. Acute effects of nanoparticulate (Zn 200) were reduced by the (Ce 200) addition. It prompted the mutual, combined interactions which elevated photosynthetic pigments levels and significantly relieved leaf chlorosis symptoms. Following Wang et al. [75] and Broadley et al. [70], Zn may induce chlorosis of leaves by stimulating Mg, Fe, and Mn deficiency. These elements are crucial in the synthesis and stability of chlorophyll. A decline of green photosynthetic pigments in plants under ZnO NPs treatment was also reported by Zoufan et al. [78] who explained it by peroxidation of the chloroplast membrane due to exacerbation of oxidative stress. Oxidative damage triggered by ZnO NPs was also reported by Salehi et al. [79]. In turn, CeO2 NPs have the ability to quench ROS, mainly produced in chloroplasts [80,81,82], and presumably mitigate stress induced by nanoparticulate ZnO.
Apart from the conventional wet chemical methods based on extraction of the chlorophyll pigments and their further spectrophotometric determination, the nondestructive measurements using the Soil Plant Analysis Development SPAD-502Plus chlorophyll meter were also performed (Figure 3). The results obtained by all those methods are highly correlated. The reduction in chlorophyll content expressed in SPAD units in Pisum sativum L., cultivated in soil supplemented by nanoparticulate ZnO, was also observed by Mukherjee et al. [38], and following Küpper et al. [83] was attributed to the Mg substitution by Zn.

3.4. Photosynthesis Parameters

Photosynthesis efficiency is usually assessed with the gas exchange analysis of plant leaves [84,85,86]. Leaf net photosynthesis (A), transpiration rate (E), stomatal conductance (gs), sub-stomatal CO2 concentration (Ci), and water use efficiency (WUE) determined under either sole or combined nanoparticles treatments are collected in Figure 4. Net photosynthesis was encouraged by CeO2 supplementations and significantly reduced by ZnO additions, Figure 4a. The latter follows reduced chlorophyll content as induced by elevated zinc concentrations [75,87]. This effect is partially released by the nanoceria addition in combined (Ce 100 + Zn 100) and (Ce 200 + Zn 200) treatments. Zinc is an essential metal necessary for proper plant development [70]. However, above certain concentrations, it affects chlorophyll synthesis and photosystem II efficiency [88,89]. Transpiration and stomatal conductance behave in a similar way with the highest values observed for (Ce 100) and (Ce 200) treatments and their substantial decline induced by either (Zn 100) and (Zn 200) supplementations (Figure 4b,c). The sub-stomatal CO2 concentrations exhibit a more uniform pattern and are significantly less prone to ZnO supplementations (Figure 4d). The largest water use efficiency was observed for (Ce 100) and (Zn 100) treatments, Figure 4e. High concentrations of (Ce 200) and (Zn 200) nanoparticles prompted a decrease in WUE. Maximum rates of ribulose 1,5-bisphosphate (RuBP) carboxylation as catalyzed by Rubisco (Vcmax), electron transfer driving the regeneration of RuBP (Jmax), and CO2 compensation points for pea plants cultivated in Hoagland’s solution supplemented with either sole or combined CeO2 and ZnO NPs are in Table 2 and Supplementary Figure S1. The highest Vcmax values were observed for the sole nanoceria augmentations [(Ce 100) and (Ce 200)] while the strongest decreases were induced by the sole (Zn 100) and (Zn 200) NPs additions. The electron transfer rates Jmax followed patterns observed for the RuBP regeneration. The lowest carbon dioxide compensation point was determined for the (Ce 100) treatment, the largest was obtained for (Zn 200).
Nanoceria is an effective free radicals scavenger and mimics the activity of several enzymes, namely superoxide dismutase (SOD), catalase (CAT), and oxidase (OXD) [32,90,91,92]. In this respect, it was classified by Korsvik et al. [93] as the first antioxidant nanoenzyme [90]. Stimulation of photosynthesis under abiotic stress mitigated by nanoceria in Arabidopsis thaliana was investigated by Wu et al. [32,94]. They pointed out that nanoparticulate CeO2 reduced the stress induced by reactive oxygen species, namely ●OH, which are not tackled by the usual plant enzymatic scavenging pathways. Those NPs had entered chloroplasts through the nonendocytic pathways, reduced the ROS concentrations, and finally increased the quantum yield of photosystem II, carbon assimilation rates, and chlorophyll content. The latter processes are governed by the reversible redox reactions between the Ce4+ and Ce3+ species which are followed by the oxygen vacancy generation or elimination [95,96,97]. Moreover, Cao et al. [22,98] identified a strong correlation between photosynthesis parameters and the applied doses of CeO2 NPs in soybean. The resulting photosynthesis enhancement was explained by the elevated Rubisco activity (Vcmax) and promotion of the NADPH regeneration rate which prompted the RuBP synthesis.
Nanometric ZnO affected the CO2 assimilation process in a roughly opposite way than CeO2 NPs. At low concentrations, zinc is a micronutrient necessary for proper plant development. At elevated levels (above 300 µg/g, plant dry weight), zinc becomes a toxic pollutant responsible for the generation of ROS [99,100]. It alters stomata morphology and formation. The decreased gs and E indicated an increased stomatal closure and restriction of the transpiration rate. Carbon dioxide enters pea leaves by diffusion through stomatal pores. The major photosynthesis limitations result either from diffusion-controlled restrictions in CO2 supply to the carboxylation sites or reduction in its consumption through the mitigated Rubisco activity and RuBP regeneration [101]. The decrease in the net photosynthesis A was correlated with the intercellular CO2 concentration Ci and accompanied by the simultaneous reduction in Vcmax and Jmax. These results suggest that ZnO NPs induced either stomatal or biochemical photosynthesis limitations. In the mixed ZnO and CeO2 treatments, the latter effects are attenuated by the free radical scavenging properties of nanoceria.

3.5. Elements Content

Copper, manganese, iron, magnesium, calcium, and potassium contents were determined in plants from all treatments. The results are presented in Figure 5 and Table S4. Roots and shoots were treated separately. A one-way ANOVA was initially used to evaluate concentrations of macro- and micronutrients in pea plants. The 0.95 probability level was applied. Both nano-oxides altered the uptake of elements and their further translocation to the green parts of pea (Table S5).
Nanoceria in both tested concentrations [(Ce 100) and (Ce 200)] significantly reduced the uptake of all three investigated heavy metals (Cu, Mn, and Fe) by the roots. On the other hand, nanoparticulate ZnO [(Zn 100) and (Zn 200)] behaved in a less obvious way. Roots uptake was increased for copper and decreased for manganese. The uptake of iron by the roots was not affected by (Zn 100) and was reduced by high zinc supplementation (Zn 200). The combined treatments, either (Ce 100 + Zn 100) or (Ce 200 + Zn 200), prompted more complex root responses. For Cu, the resulting uptakes were between those induced by the administration of either CeO2 or ZnO alone. The manganese levels were as low as those observed for the sole (Zn 100) and (Zn 200) supplementations. In the combined (Ce 200 + Zn 200) treatment Fe root level was as high as that in the control sample. However, (Ce 100 + Zn 100) treatment prompted much lower Fe concentrations. In green parts of the pea plants, the levels of Cu, Mn, and Fe were lower than those in roots. The only exception was manganese whose concentrations in shoots were higher for all samples supplemented with nanometric ZnO. Zinc hampers manganese uptake by roots. The latter element is essential for the water-splitting process during the light-dependent phase of photosynthesis. These circumstances facilitate Mn migration from roots to shoots. A quite similar situation was observed for magnesium and calcium. The former is an important chlorophyll cofactor while the latter is a structural component of photosystem II. Both ions are crucial for the overall photosynthesis yield. The additions of (Ce 100) and (Ce 200) NPs alone decreased potassium levels in roots and shoots. Both were inversely proportional to the Ce supplementations. The nanometric ZnO in either sole or combined administrations further restrained potassium contents in pea roots. However, unlike in the case of the nanoceria additions, higher K levels were observed in shoots.

4. Conclusions

Nanomaterials alter plant metabolism in a number of ways with photosystems I and II being their important targets. This paper continues our investigations on plant metabolism and uptake of nutrients in a model hydroponic environment subjected to nanoparticles pollution. Steadily increasing usage of nanomaterials in smart agriculture prompts thorough studies on their interactions with plant organisms. Nanoparticles rarely exist in the environment alone and their combined interactions can hardly be neglected.
Regrettably, relevant studies on their impact on plant photosynthesis are scarce. In this study, pea plants were cultivated in Hoagland’s solutions supplemented with either sole or mixed cerium and zinc nano-oxides at 100 mg/L or 200 mg/L Ce or Zn levels. Despite relatively high sole CeO2 administration (200 mg/L), no morphological symptoms of phytotoxicity were detected in Pisum sativum L. Leaf net photosynthesis, water use efficiency, and fresh biomass production were stimulated at the 100 mg/L Ce concentration and only slightly suppressed at its higher level. Contrarily, ZnO NPs applied alone caused serious impairment of metal homeostasis, decreased the level of photosynthetic pigments, induced leaf chlorosis, and finally hampered photosynthetic efficiency. We proved that ZnO NPs induced stomatal and biochemical limitations of photosynthesis. Such dysfunctions could lead to the overproduction of ROS in chloroplast and induce oxidative stress. In mixed CeO2–ZnO NPs treatments, the beneficial effect of nanoceria was observed. In particular, pigments concentrations, leaf net photosynthesis, and maximum electron transport rate (Jmax) depressed by ZnO NPs were significantly alleviated when CeO2 NPs were present in the growing medium. It is well recognized that nanoceria has the potential to quench ROS. Therefore, we conclude that CeO2 NPs moderate ZnO NPs toxicity by protecting the photosynthetic apparatus in Pisum sativum leaves from oxidative stress trigged by Zn. Additionally, we observed that both nano-oxides affected the nutrients uptake and transport at all concentrations applied.
Reactive oxygen species are by-products of aerobic metabolic processes in plants [102,103]. They usually increase membrane permeability and initiate stress signals often leading to programmed cell death [104]. At certain concentrations, the presence of NPs in growing media elevates ROS levels and induces oxidative damage in plant species. On the other hand, plant organisms have developed advanced antioxidant systems which involve either enzymatic or non-enzymatic pathways stabilizing ROS levels [105]. Those systems are enhanced under exposure to NPs, perhaps as an adaptive response to alleviate stress. We speculate that either CeO2 or ZnO nanoparticles trigger oxidative stress in pea but only cerium dioxide acts as an antioxidant and reduces the stress symptoms while zinc oxide is mainly a prooxidant.
Our future studies will be aimed at the binary activity of nanoceria in agricultural plants. Namely, at high concentrations, it is a plant stressor that triggers ROS production while at certain, low levels nanoceria exhibits a ROS scavenging ability and supports the plant’s defense mechanisms. The latter effect may find applications in agriculture and deserves further investigation.

Supplementary Materials

The following are available online at https://www.mdpi.com/article/10.3390/cells10113105/s1, Table S1: Characterization of CeO2 NPs and ZnO NPs, Table S2: Elements content in certified reference materials Oriental Basma Tobacco Leaves—INCT-OBTL-5 (p = 0.95, n = 8), Table S3: Root length and tolerance index (TI) of Pisum sativum L. treated with nanoparticulate CeO2 and ZnO, Table S4: ANOVA parameters for elements concentrations in roots and shoots of Pisum sativum L. plants across all treatments., Table S5: Translocation factors (TF) of nutrients from root to shoot in Pisum sativum L. plants grown under the sole or combined CeO2 and ZnO NPs treatments, Figure S1: Comparison of CO2 response curves (A/Ci) between control and treated plants.

Author Contributions

Conceptualization, E.S. and W.M.W.; methodology, E.S., M.P. and S.G.; validation, E.S. and W.M.W.; formal analysis, E.S. and M.P.; investigation, E.S. and M.P.; writing—original draft preparation, E.S., M.P. and W.M.W.; writing—review and editing, E.S., M.P., S.G. and W.M.W.; visualization, E.S. and M.P.; supervision, E.S. and W.M.W. All authors have read and agreed to the published version of the manuscript.

Funding

This work received support from the Regional Fund for Environmental Protection and Water Management in Lodz, Poland (Grant Number: 58/BN/D2018); additional funding from the Institute of General and Ecological Chemistry of Lodz University of Technology is also acknowledged.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

The data presented in this study are available on request from the corresponding author.

Acknowledgments

The authors wish to thank Lilianna Chęcińska for consultations on the solid structures of nano-oxides and their influence on properties of nanomaterials in micellar forms. Jakub Kubicki is kindly acknowledged for his support in heavy metals determination; Sylwia Michlewska and Sławomir Kadłubowski for their help in zeta potential measurements. The European University Foundation is acknowledged for advising on the legal and social dimensions of this study.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Verma, A.; Yadav, M. Application of nanomaterials in architecture—An overview. Mater. Today Proc. 2021, 43, 2921–2925. [Google Scholar] [CrossRef]
  2. Hoang, A.T. Combustion behavior, performance and emission characteristics of diesel engine fuelled with biodiesel containing cerium oxide nanoparticles: A review. Fuel Process. Technol. 2021, 218, 106840. [Google Scholar] [CrossRef]
  3. Yu, J.; Luo, M.; Lv, Z.; Huang, S.; Hsu, H.H.; Kuo, C.C.; Han, S.T.; Zhou, Y. Recent advances in optical and optoelectronic data storage based on luminescent nanomaterials. Nanoscale 2020, 12, 23391–23423. [Google Scholar] [CrossRef]
  4. Caro, C.; Gámez, F.; Quaresma, P.; Páez-Muñoz, J.M.; Domínguez, A.; Pearson, J.R.; Pernía Leal, M.; Beltrán, A.M.; Fernandez-Afonso, Y.; De La Fuente, J.M.; et al. Fe3O4-Au core-shell nanoparticles as a multimodal platform for in vivo imaging and focused photothermal therapy. Pharmaceutics 2021, 13, 416. [Google Scholar] [CrossRef]
  5. Jandt, K.D.; Watts, D.C. Nanotechnology in dentistry: Present and future perspectives on dental nanomaterials. Dent. Mater. 2020, 36, 1365–1378. [Google Scholar] [CrossRef]
  6. Chen, L.; Liu, Z.; Guo, Z.; Huang, X.J. Regulation of intrinsic physicochemical properties of metal oxide nanomaterials for energy conversion and environmental detection applications. J. Mater. Chem. A 2020, 8, 17326–17359. [Google Scholar] [CrossRef]
  7. Khoo, K.S.; Chia, W.Y.; Tang, D.Y.Y.; Show, P.L.; Chew, K.W.; Chen, W.H. Nanomaterials utilization in biomass for biofuel and bioenergy production. Energies 2020, 13, 892. [Google Scholar] [CrossRef] [Green Version]
  8. Sengwa, R.J.; Dhatarwal, P.; Choudhary, S. A comparative study of different metal oxide nanoparticles dispersed PVDF/PEO blend matrix-based advanced multifunctional nanodielectrics for flexible electronic devices. Mater. Today Commun. 2020, 25, 101380. [Google Scholar] [CrossRef]
  9. Degfie, T.A.; Mamo, T.T.; Mekonnen, Y.S. Optimized biodiesel production from waste cooking oil (WCO) using calcium oxide (CaO) nano-catalyst. Sci. Rep. 2019, 9, 18982. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  10. Sui, X.; Downing, J.R.; Hersam, M.C.; Chen, J. Additive manufacturing and applications of nanomaterial-based sensors. Mater. Today 2021. [Google Scholar] [CrossRef]
  11. Hou, Q.; Qi, X.; Zhen, M.; Qian, H.; Nie, Y.; Bai, C.; Zhang, S.; Bai, X.; Ju, M. Biorefinery roadmap based on catalytic production and upgrading 5-hydroxymethylfurfural. Green Chem. 2021, 23, 119–231. [Google Scholar] [CrossRef]
  12. Shi, Y.; Xu, H.; Liu, T.; Zeb, S.; Nie, Y.; Zhao, Y.; Qin, C.; Jiang, X. Advanced development of metal oxide nanomaterials for H2 gas sensing applications. Mater. Adv. 2021, 2, 1530–1569. [Google Scholar] [CrossRef]
  13. Singh, R.P.; Handa, R.; Manchanda, G. Nanoparticles in sustainable agriculture: An emerging opportunity. J. Control. Release 2021, 329, 1234–1248. [Google Scholar] [CrossRef]
  14. Singh, H.; Sharma, A.; Bhardwaj, S.K.; Arya, S.K.; Bhardwaj, N.; Khatri, M. Recent advances in the applications of nano-agrochemicals for sustainable agricultural development. Environ. Sci. Process. Impacts 2021, 23, 213–239. [Google Scholar] [CrossRef]
  15. Tarrahi, R.; Mahjouri, S.; Khataee, A. A review on in vivo and in vitro nanotoxicological studies in plants: A headlight for future targets. Ecotoxicol. Environ. Saf. 2021, 208, 111697. [Google Scholar] [CrossRef]
  16. Wang, M.; Li, S.; Chen, Z.; Zhu, J.; Hao, W.; Jia, G.; Chen, W.; Zheng, Y.; Qu, W.; Liu, Y. Safety assessment of nanoparticles in food: Current status and prospective. Nano Today 2021, 39, 101169. [Google Scholar] [CrossRef]
  17. Ameen, F.; Alsamhary, K.; Alabdullatif, J.A.; ALNadhari, S. A review on metal-based nanoparticles and their toxicity to beneficial soil bacteria and fungi. Ecotoxicol. Environ. Saf. 2021, 213, 112027. [Google Scholar] [CrossRef] [PubMed]
  18. Metal Oxide Nanoparticles Market—Growth, Trends, COVID-19 Impact, and Forecasts (2021–2026). Available online: https://www.mordorintelligence.com/industry-reports/metal-oxide-nanoparticles-market (accessed on 5 May 2021).
  19. Choi, S.J.; Choy, J.H. Effect of physico-chemical parameters on the toxicity of inorganic nanoparticles. J. Mater. Chem. 2011, 21, 5547–5554. [Google Scholar] [CrossRef]
  20. Chen, C.; Li, Y.F.; Qu, Y.; Chai, Z.; Zhao, Y. Advanced nuclear analytical and related techniques for the growing challenges in nanotoxicology. Chem. Soc. Rev. 2013, 42, 8266–8303. [Google Scholar] [CrossRef]
  21. Bundschuh, M.; Filser, J.; Lüderwald, S.; McKee, M.S.; Metreveli, G.; Schaumann, G.E.; Schulz, R.; Wagner, S. Nanoparticles in the environment: Where do we come from, where do we go to? Environ. Sci. Eur. 2018, 30, 6. [Google Scholar] [CrossRef] [Green Version]
  22. Cao, Z.; Stowers, C.; Rossi, L.; Zhang, W.; Lombardini, L.; Ma, X. Physiological effects of cerium oxide nanoparticles on the photosynthesis and water use efficiency of soybean (Glycine max (L.) Merr.). Environ. Sci. Nano 2017, 4, 1086–1094. [Google Scholar] [CrossRef]
  23. Bindra, H.S.; Singh, B. Nanofertilizers and nanopesticides: Future of plant protection. In Advances in Nano-Fertilizers and Nano-Pesticides in Agriculture, 1st ed.; Jogaiah, S., Singh, H.B., Fraceto, L.F., de Lima, R., Eds.; Woodhead Publishing: Cambridge, UK, 2021; pp. 57–84. [Google Scholar]
  24. Verma, S.K.; Das, A.K.; Patel, M.K.; Shah, A.; Kumar, V.; Gantait, S. Engineered nanomaterials for plant growth and development: A perspective analysis. Sci. Total Environ. 2018, 630, 1413–1435. [Google Scholar] [CrossRef] [PubMed]
  25. Hussain, A.; Ali, S.; Rizwan, M.; Zia ur Rehman, M.; Javed, M.R.; Imran, M.; Chatha, S.A.S.; Nazir, R. Zinc oxide nanoparticles alter the wheat physiological response and reduce the cadmium uptake by plants. Environ. Pollut. 2018, 242, 1518–1526. [Google Scholar] [CrossRef] [PubMed]
  26. Rizwan, M.; Ali, S.; Qayyum, M.F.; Ok, Y.S.; Adrees, M.; Ibrahim, M.; Zia-ur-Rehman, M.; Farid, M.; Abbas, F. Effect of metal and metal oxide nanoparticles on growth and physiology of globally important food crops: A critical review. J. Hazard. Mater. 2017, 322, 2–16. [Google Scholar] [CrossRef]
  27. Marchiol, L.; Filippi, A.; Adamiano, A.; Esposti, L.D.; Iafisco, M.; Mattiello, A.; Petrussa, E.; Braidot, E. Influence of hydroxyapatite nanoparticles on germination and plant metabolism of tomato (Solanum lycopersicum L.): Preliminary evidence. Agronomy 2019, 9, 161. [Google Scholar] [CrossRef] [Green Version]
  28. Marslin, G.; Sheeba, C.J.; Franklin, G. Nanoparticles alter secondary metabolism in plants via ROS burst. Front. Plant Sci. 2017, 8, 832. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  29. Dhiman, S.; Bakshi, P.; Kapoor, N.; Sharma, P.; Kohli, S.K.; Mir, B.A.; Bhardwaj, R. Nanoparticle-induced oxidative stress. In Plant Responses to Nanomaterials. Recent Interventions and Physiological and Biochemical Responses; Singh, V.P., Singh, S., Prasad, S.M., Chauhan, D.K., Tripathi, D.K., Eds.; Springer: New York, NY, USA, 2021; pp. 269–313. [Google Scholar]
  30. Kalaji, M.H.; Goltsev, V.N.; Żuk-Golaszewska, K.; Zivcak, M.; Brestic, M. Chlorophyll Fluorescence: Understanding Crop Performance—Basics and Applications; CRC Press Taylor & Francis Group: New York, NY, USA, 2017. [Google Scholar]
  31. Rodea-Palomares, I.; Gonzalo, S.; Santiago-Morales, J.; Leganés, F.; García-Calvo, E.; Rosal, R.; Fernández-Piñas, F. An insight into the mechanisms of nanoceria toxicity in aquatic photosynthetic organisms. Aquat. Toxicol. 2012, 122–123, 133–143. [Google Scholar] [CrossRef]
  32. Wu, H.; Tito, N.; Giraldo, J.P. Anionic cerium oxide nanoparticles protect plant photosynthesis from abiotic stress by scavenging reactive oxygen species. ACS Nano 2017, 11, 11283–11297. [Google Scholar] [CrossRef]
  33. Wang, X.P.; Li, Q.Q.; Pei, Z.M.; Wang, S.C. Effects of zinc oxide nanoparticles on the growth, photosynthetic traits, and antioxidative enzymes in tomato plants. Biol. Plant. 2018, 62, 801–808. [Google Scholar] [CrossRef]
  34. Faizan, M.; Faraz, A.; Hayat, S. Effective use of zinc oxide nanoparticles through root dipping on the performance of growth, quality, photosynthesis and antioxidant system in tomato. J. Plant Biochem. Biotechnol. 2020, 29, 553–567. [Google Scholar] [CrossRef]
  35. Tighe-Neira, R.; Carmora, E.; Recio, G.; Nunes-Nesi, A.; Reyes-Diaz, M.; Alberdi, M.; Rengel, Z.; Inostroza-Blancheteau, C. Metallic nanoparticles influence the structure and function of the photosynthetic apparatus in plants. Plant Physiol. Biochem. 2018, 130, 408–417. [Google Scholar] [CrossRef]
  36. Zhao, L.; Peralta-Videa, J.R.; Rico, C.M.; Hernandez-Viezcas, J.A.; Sun, Y.; Niu, G.; Servin, A.; Nunez, J.E.; Duarte-Gardea, M.; Gardea-Torresdey, J.L. CeO2 and ZnO nanoparticles change the nutritional qualities of cucumber (Cucumis sativus). J. Agric. Food Chem. 2014, 62, 2752–2759. [Google Scholar] [CrossRef] [PubMed]
  37. Du, W.; Tan, W.; Peralta-Videa, J.R.; Gardea-Torresdey, J.L.; Ji, R.; Yin, Y.; Guo, H. Interaction of metal oxide nanoparticles with higher terrestrial plants: Physiological and biochemical aspects. Plant Physiol. Biochem. 2017, 110, 210–225. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  38. Mukherjee, A.; Peralta-Videa, J.R.; Bandyopadhyay, S.; Rico, C.M.; Zhao, L.; Gardea-Torresdey, J.L. Physiological effects of nanoparticulate ZnO in green peas (Pisum sativum L.) cultivated in soil. Metallomics 2014, 6, 132–138. [Google Scholar] [CrossRef] [PubMed]
  39. Reddy Pullagurala, V.L.; Adisa, I.O.; Rawat, S.; Kalagara, S.; Hernandez-Viezcas, J.A.; Peralta-Videa, J.R.; Gardea-Torresdey, J.L. ZnO nanoparticles increase photosynthetic pigments and decrease lipid peroxidation in soil grown cilantro (Coriandrum sativum). Plant Physiol. Biochem. 2018, 132, 120–127. [Google Scholar] [CrossRef] [PubMed]
  40. Li, J.; Mu, Q.; Du, Y.; Luo, J.; Liu, Y.; Li, T. Growth and photosynthetic inhibition of cerium oxide nanoparticles on soybean (Glycine max). Bull. Environ. Contam. Toxicol. 2020, 105, 119–126. [Google Scholar] [CrossRef]
  41. Zulfiqar, F.; Navarro, M.; Ashraf, M.; Akram, N.A.; Munné-Bosch, S. Nanofertilizer use for sustainable agriculture: Advantages and limitations. Plant Sci. 2019, 289, 110270. [Google Scholar] [CrossRef]
  42. Kumar, S.; Nehra, M.; Dilbaghi, N.; Marrazza, G.; Hassan, A.A.; Kim, K.H. Nano-based smart pesticide formulations: Emerging opportunities for agriculture. J. Control. Release 2019, 294, 131–153. [Google Scholar] [CrossRef]
  43. Sun, Y.; Liang, J.; Tang, L.; Li, H.; Zhu, Y.; Jiang, D.; Song, B.; Chen, M.; Zeng, G. Nano-pesticides: A great challenge for biodiversity? Nano Today 2019, 28, 100757. [Google Scholar] [CrossRef]
  44. Silva, L.P.; Bonatto, C.C. Green nanotechnology for sustained release of eco-friendly agrochemicals. In Sustainable Agrochemistry. A Compendium of Technologies; Vaz, S., Jr., Ed.; Springer: New York, NY, USA, 2019; pp. 113–129. [Google Scholar]
  45. Mohammadi, M.H.Z.; Panahirad, S.; Navai, A.; Bahrami, M.K.; Kulak, M.; Gohari, G. Cerium oxide nanoparticles (CeO2-NPs) improve growth parameters and antioxidant defense system in Moldavian Balm (Dracocephalummoldavica, L.) under salinity stress. Plant Stress 2021, 1, 100006. [Google Scholar] [CrossRef]
  46. Jahani, S.; Saadatmand, S.; Mahmoodzadeh, H.; Khavari-Nejad, R.A. Effect of foliar application of cerium oxide nanoparticles on growth, photosynthetic pigments, electrolyte leakage, compatible osmolytes and antioxidant enzymes activities of Calendula officinalis L. Biologia 2019, 74, 1063–1075. [Google Scholar] [CrossRef]
  47. Jurkow, R.; Pokluda, R.; Sȩkara, A.; Kalisz, A. Impact of foliar application of some metal nanoparticles on antioxidant system in oakleaf lettuce seedlings. BMC Plant Biol. 2020, 20, 290. [Google Scholar] [CrossRef] [PubMed]
  48. Liu, Y.; Yue, L.; Wang, C.; Zhu, X.; Wang, Z.; Xing, B. Photosynthetic response mechanisms in typical C3 and C4 plants upon La2O3 nanoparticle exposure. Environ. Sci. Nano 2020, 7, 81–92. [Google Scholar] [CrossRef]
  49. Naasz, S.; Altenburger, R.; Kühnel, D. Environmental mixtures of nanomaterials and chemicals: The Trojan-horse phenomenon and its relevance for ecotoxicity. Sci. Total Environ. 2018, 635, 1170–1181. [Google Scholar] [CrossRef]
  50. Singh, D.; Kumar, A. Binary mixture of nanoparticles in sewage sludge: Impact on spinach growth. Chemosphere 2020, 254, 126794. [Google Scholar] [CrossRef] [PubMed]
  51. Singh, D.; Kumar, A. Quantification of metal uptake in Spinacia oleracea irrigated with water containing a mixture of CuO and ZnO nanoparticles. Chemosphere 2020, 243, 125239. [Google Scholar] [CrossRef]
  52. Skiba, E.; Michlewska, S.; Pietrzak, M.; Wolf, W.M. Additive interactions of nanoparticulate ZnO with copper, manganese and iron in Pisum sativum L., a hydroponic study. Sci. Rep. 2020, 10, 13574. [Google Scholar] [CrossRef]
  53. Skiba, E.; Pietrzak, M.; Gapińska, M.; Wolf, W.M. Metal homeostasis and gas exchange dynamics in Pisum sativum L. exposed to cerium oxide nanoparticles. Int. J. Mol. Sci. 2020, 21, 8497. [Google Scholar] [CrossRef]
  54. Skiba, E.; Wolf, W.M. Cerium oxide nanoparticles affect heavy metals uptake by pea in a divergent way than their ionic and bulk counterparts. Water Air Soil Pollut. 2019, 230, 248. [Google Scholar] [CrossRef] [Green Version]
  55. Kreplak, J.; Madoui, M.A.; Cápal, P.; Novák, P.; Labadie, K.; Aubert, G.; Bayer, P.E.; Gali, K.K.; Syme, R.A.; Main, D.; et al. A reference genome for pea provides insight into legume genome evolution. Nat. Genet. 2019, 51, 1411–1422. [Google Scholar] [CrossRef]
  56. Burstin, J.; Kreplak, J.; Macas, J.; Lichtenzveig, J. Pisum sativum (Pea). Trends Genet. 2020, 36, 312–313. [Google Scholar] [CrossRef] [PubMed]
  57. Zhang, X.; Wan, S.; Hao, J.; Hu, J.; Yang, T.; Zong, X. Large-scale evaluation of pea (Pisum sativum L.) germplasm for cold tolerance in the field during winter in Qingdao. Crop. J. 2016, 4, 377–383. [Google Scholar] [CrossRef] [Green Version]
  58. Meier, U. Growth Stages of Mono- and Dicotyledonous Plants: BBCH Monograph; Blackwell Wissenschafts: Berlin, Germany, 1997. [Google Scholar]
  59. Samczyński, Z.; Dybczyński, R.S.; Polkowska-Motrenko, H.; Chajduk, E.; Pyszynska, M.; Danko, B.; Czerska, E.; Kulisa, K.; Doner, K.; Kalbarczyk, P. Two new reference materials based on tobacco leaves: Certification for over a dozen of toxic and essential elements. Sci. World J. 2012, 2012, 216380. [Google Scholar] [CrossRef] [Green Version]
  60. Turner, R.G.; Marshal, C. Accumulation of zinc by subcellular root of Agrostis tannis Sibth. in relation of zinc tolerance. New Phytol. 1972, 71, 671–676. [Google Scholar] [CrossRef]
  61. KaramiMehrian, S.; Heidari, R.; Rahmani, F.; Najafi, S. Effect of chemical synthesis silver nanoparticles on germination indices and seedlings growth in seven varieties of Lycopersiconesculentum Mill (tomato) plants. J. Clust. Sci. 2016, 27, 327–340. [Google Scholar] [CrossRef]
  62. Liu, Z.; He, X.; Chen, W.; Yuan, F.; Yan, K.; Tao, D. Accumulation and tolerance characteristics of cadmium in a potential hyperaccumulator-Lonicera japonica Thunb. J. Hazard. Mater. 2009, 169, 170–175. [Google Scholar] [CrossRef]
  63. Mayerová, M.; Petrová, Š.; Madaras, M.; Lipavský, J.; Šimon, T.; Vaněk, T. Non-enhanced phytoextraction of cadmium, zinc, and lead by high-yielding crops. Environ. Sci. Pollut. Res. 2017, 24, 14706–14716. [Google Scholar] [CrossRef]
  64. Oren, R.; Werk, K.S.; Buchmann, N.; Zimmermann, R. Chlorophyll-nutrient relationships identify nutritionally caused decline in Piceaabies stands. Can. J. For. Res. 1993, 23, 1187–1195. [Google Scholar] [CrossRef]
  65. Lichtenthaler, H.K.; Wellburn, A.R. Determinations of total carotenoids and chlorophylls a and b of leaf extracts in different solvents. Biochem. Soc. Trans. 1983, 11, 591–592. [Google Scholar] [CrossRef] [Green Version]
  66. R Core Team. R: A Language and Environment for Statistical Computing; R Foundation for Statistical Computing: Vienna, Austria, 2019; Available online: https://www.R-project.org (accessed on 10 January 2021).
  67. Duursma, R.A. Plantecophys—An R package for analysing and modelling leaf gas exchange data. PLoS ONE 2015, 10, e0143346. [Google Scholar] [CrossRef]
  68. Marchiol, L.; Mattiello, A.; Pošćić, F.; Fellet, G.; Zavalloni, C.; Carlino, E.; Musetti, R. Changes in physiological and agronomical parameters of barley (Hordeum vulgare) exposed to cerium and titanium dioxide nanoparticles. Int. J. Environ. Res. Public Health 2016, 13, 332. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  69. Herber, R.F.M.; Sallé, H.J.A. Statistics and data evaluation. Tech. Instrum. Anal. Chem. 1994, 15, 257–271. [Google Scholar]
  70. Broadley, M.R.; White, P.J.; Hammond, J.P.; Zelko, I.; Lux, A. Zinc in plants. New Phytol. 2007, 173, 677–702. [Google Scholar] [CrossRef] [PubMed]
  71. Broadley, M.; Brown, P.; Cakmak, I.; Rengel, Z.; Zhao, F. Function of nutrients: Micronutrients. In Marschner’s Mineral Nutrition of Higher Plants, 3rd ed.; Marschner, P., Ed.; Academic Press: Cambridge, MA, USA; Elsevier Ltd.: Amsterdam, The Netherlands, 2011; pp. 191–248. [Google Scholar]
  72. Hu, X.; Tanaka, A.; Tanaka, R. Simple extraction methods that prevent the artifactual conversion of chlorophyll to chlorophyllide during pigment isolation from leaf samples. Plant Methods 2013, 9, 1–13. [Google Scholar] [CrossRef] [Green Version]
  73. Genter, R.B. Ecotoxicology of inorganic chemical stress to algae. In Algal Ecology Freshwater Benthic Ecosystems, 1st ed.; Stevenson, R.J., Bothwell, M.L., Lowe, R.L., Thorp, J., Eds.; Academic Press: San Diego, CA, USA, 1996; pp. 403–468. [Google Scholar]
  74. Hu, C.; Liu, X.; Li, X.; Zhao, Y. Evaluation of growth and biochemical indicators of Salvinia natans exposed to zinc oxide nanoparticles and zinc accumulation in plants. Environ. Sci. Pollut. Res. 2014, 21, 732–739. [Google Scholar] [CrossRef] [PubMed]
  75. Wang, C.; Zhang, S.H.; Wang, P.F.; Hou, J.; Zhang, W.J.; Li, W.; Lin, Z.P. The effect of excess Zn on mineral nutrition and antioxidative response in rapeseed seedlings. Chemosphere 2009, 75, 1468–1476. [Google Scholar] [CrossRef] [PubMed]
  76. Ebbs, S.; Uchil, S. Cadmium and zinc induced chlorosis in Indian mustard [Brassica juncea (L.) Czern] involves preferential loss of chlorophyll b. Photosynthetica 2008, 46, 49–55. [Google Scholar] [CrossRef]
  77. Andrejić, G.; Gajić, G.; Prica, M.; Dželetović, Ž.; Rakić, T. Zinc accumulation, photosynthetic gas exchange, and chlorophyll a fluorescence in Zn-stressed Miscanthus x giganteus plants. Photosynthetica 2018, 56, 1249–1258. [Google Scholar] [CrossRef]
  78. Zoufan, P.; Baroonian, M.; Zargar, B. ZnO nanoparticles-induced oxidative stress in Chenopodium murale L., Zn uptake, and accumulation under hydroponic culture. Environ. Sci. Pollut. Res. 2020, 27, 11066–11078. [Google Scholar] [CrossRef]
  79. Salehi, H.; De Diego, N.; Chehregani Rad, A.; Benjamin, J.J.; Trevisan, M.; Lucini, L. Exogenous application of ZnO nanoparticles and ZnSO4 distinctly influence the metabolic response in Phaseolus vulgaris L. Sci. Total Environ. 2021, 778, 146331. [Google Scholar] [CrossRef]
  80. Choudhury, F.K.; Rivero, R.M.; Blumwald, E.; Mittler, R. Reactive oxygen species, abiotic stress and stress combination. Plant J. 2017, 90, 856–867. [Google Scholar] [CrossRef]
  81. Mhamdi, A.; Van Breusegem, F. Reactive oxygen species in plant development. Development 2018, 145, 15. [Google Scholar] [CrossRef] [Green Version]
  82. Kim, C. ROS-driven oxidative modification: Its impact on chloroplasts-nucleus communication. Front. Plant Sci. 2020, 10, 1729. [Google Scholar] [CrossRef] [PubMed]
  83. Küpper, H.; Küpper, F.; Spiller, M. Environmental relevance of heavy metal-substituted chlorophylls using the example of water plants. J. Exp. Bot. 1996, 47, 259–266. [Google Scholar] [CrossRef] [Green Version]
  84. Sharkey, T.D. What gas exchange data can tell us about photosynthesis. Plant Cell Environ. 2016, 39, 1161–1163. [Google Scholar] [CrossRef] [PubMed]
  85. Long, S.P.; Bernacchi, C.J. Gas exchange measurements, what can they tell us about the underlying limitations to photosynthesis? Procedures and sources of error. J. Exp. Bot. 2003, 54, 2393–2401. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  86. Haworth, M.; Marino, G.; Centritto, M. An introductory guide to gas exchange analysis of photosynthesis and its application to plant phenotyping and precision irrigation to enhance water use efficiency. J. Water Clim. Chang. 2018, 9, 786–808. [Google Scholar] [CrossRef] [Green Version]
  87. Vassilev, A.; Nikolova, A.; Koleva, L.; Lidon, F. Effects of excess Zn on growth and photosynthetic performance of young bean plants. J. Phytol. 2011, 3, 58–62. [Google Scholar]
  88. Balafrej, H.; Bogusz, D.; Triqui, Z.-E.A.; Guedira, A.; Bendaou, N.; Smouni, A.; Fahr, M. Zinc hyperaccumulation in plants: A review. Plants 2020, 9, 562. [Google Scholar] [CrossRef]
  89. Anwaar, S.A.; Ali, S.; Ali, S.; Ishaque, W.; Farid, M.; Farooq, M.A.; Najeeb, U.; Abbas, F.; Sharif, M. Silicon (Si) alleviates cotton (Gossypium hirsutum L.) from zinc (Zn) toxicity stress by limiting Zn uptake and oxidative damage. Environ. Sci. Pollut. Res. 2015, 22, 3441–3450. [Google Scholar] [CrossRef]
  90. Liu, Y.; Xiao, Z.; Chen, F.; Yue, L.; Zou, H.; Lyu, J.; Wang, Z. Metallic oxide nanomaterials act as antioxidant nanozymes in higher plants: Trends, meta-analysis, and prospect. Sci. Total Environ. 2021, 780, 146578. [Google Scholar] [CrossRef]
  91. Djanaguiraman, M.; Nair, R.; Giraldo, J.P.; Prasad, P.V.V. Cerium oxide nanoparticles decrease drought-induced oxidative damage in Sorghum Leading to higher photosynthesis and grain yield. ACS Omega 2018, 3, 14406–14416. [Google Scholar] [CrossRef]
  92. Baldim, V.; Bedioui, F.; Mignet, N.; Margaill, I.; Berret, J.F. The enzyme-like catalytic activity of cerium oxide nanoparticles and its dependency on Ce3+ surface area concentration. Nanoscale 2018, 10, 6971–6980. [Google Scholar] [CrossRef] [Green Version]
  93. Korsvik, C.; Patil, S.; Seal, S.; Self, W.T. Superoxide dismutase mimetic properties exhibited by vacancy engineered ceria nanoparticles. Chem. Commun. 2007, 1056–1058. [Google Scholar] [CrossRef] [PubMed]
  94. Wu, H.; Shabala, L.; Shabala, S.; Giraldo, J.P. Hydroxyl radical scavenging by cerium oxide nanoparticles improves Arabidopsis salinity tolerance by enhancing leaf mesophyll potassium retention. Environ. Sci. Nano 2018, 5, 1567–1583. [Google Scholar] [CrossRef]
  95. Nelson, B.C.; Johnson, M.E.; Walker, M.L.; Riley, K.R.; Sims, C.M. Antioxidant cerium oxide nanoparticles in biology and medicine. Antioxidants 2016, 5, 15. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  96. Zhou, P.; Adeel, M.; Shakoor, N.; Guo, M.; Hao, Y.; Azeem, I.; Li, M.; Liu, M.; Rui, Y. Application of nanoparticles alleviates heavy metals stress and promotes plant growth: An overview. Nanomaterials 2021, 11, 26. [Google Scholar] [CrossRef]
  97. Xue, Y.; Luan, Q.; Yang, D.; Yao, X.; Zhou, K. Direct evidence for hydroxyl radical scavenging activity of cerium oxide nanoparticles. J. Phys. Chem. C 2011, 115, 4433–4438. [Google Scholar] [CrossRef]
  98. Cao, Z.; Rossi, L.; Stowers, C.; Zhang, W.; Lombardini, L.; Ma, X. The impact of cerium oxide nanoparticles on the physiology of soybean (Glycine max (L.) Merr.) under different soil moisture conditions. Environ. Sci. Pollut. Res. 2018, 25, 930–939. [Google Scholar] [CrossRef]
  99. Khan, M.I.R.; Jahan, B.; Alajmi, M.F.; Rehman, M.T.; Khan, N.A. Exogenously-sourced ethylene modulates defense mechanisms and promotes tolerance to zinc stress in mustard (Brassica juncea L.). Plants 2019, 8, 540. [Google Scholar] [CrossRef] [Green Version]
  100. Feigl, G.; Lehotai, N.; Molnár, Á.; Ördög, A.; Rodríguez-Ruiz, M.; Palma, J.M.; Corpas, F.J.; Erdei, L.; Kolbert, Z. Zinc induces distinct changes in the metabolism of reactive oxygen and nitrogen species (ROS and RNS) in the roots of two Brassica species with different sensitivity to zinc stress. Ann. Bot. 2015, 116, 613–625. [Google Scholar] [CrossRef] [Green Version]
  101. Deans, R.M.; Farquhar, G.D.; Busch, F.A. Estimating stomatal and biochemical limitations during photosynthetic induction. Plant Cell Environ. 2019, 42, 3227–3240. [Google Scholar] [CrossRef]
  102. Sharma, P.; Jha, A.B.; Dubey, R.S.; Pessarakli, M. Reactive Oxygen Species, Oxidative Damage, and Antioxidative Defense Mechanism in Plants under Stressful Conditions. J. Bot. 2012, 217037. [Google Scholar] [CrossRef] [Green Version]
  103. Apel, K.; Hirt, H. Reactive Oxygen Species: Metabolism, Oxidative Stress, and Signal Transduction. Annu. Rev. Plant Biol. 2004, 55, 373–399. [Google Scholar] [CrossRef] [Green Version]
  104. Yanik, F.; Vardar, F. Mechanism and interaction of nanoparticle-induced programmed cel death in plants. In Phytotoxicity of Nanoparticles, 1st ed.; Faisal, M., Saquib, Q., Alator, A.A., Al-Khedhairy, A.A., Eds.; Springer International Publishing AG: Cham, Switzerland, 2018; pp. 175–196. [Google Scholar]
  105. Yang, J.; Cao, W.; Rui, Y. Interactions between nanoparticles and plants: Phytotoxicity and defense mechanisms. J. Plant Interact. 2017, 12, 158–169. [Google Scholar] [CrossRef]
Cells 10 03105 g001 550
Figure 1. The influence of nanoparticulate CeO2 and ZnO on: (a) root and stem length and (b) fresh weight of root and shoot as determined for a single pea plant. Concentrations of nanoparticles are given in mg/L of elemental cerium or zinc, the cultivation time was 12 days. Roots are represented by grey while above-ground parts are in green. Vertical bars represent standard deviations (n = 6). Distinct letters show the statistically significant differences among treatments as calculated with Tukey’s HSD post hoc test. The probability level p = 0.95 was applied.
Figure 1. The influence of nanoparticulate CeO2 and ZnO on: (a) root and stem length and (b) fresh weight of root and shoot as determined for a single pea plant. Concentrations of nanoparticles are given in mg/L of elemental cerium or zinc, the cultivation time was 12 days. Roots are represented by grey while above-ground parts are in green. Vertical bars represent standard deviations (n = 6). Distinct letters show the statistically significant differences among treatments as calculated with Tukey’s HSD post hoc test. The probability level p = 0.95 was applied.
Cells 10 03105 g001
Cells 10 03105 g002 550
Figure 2. The influence of nanoparticulate CeO2 and ZnO on: (a) photosynthetic pigments: chlorophyll a (Chl a), chlorophyll b (Chl b), and carotenoids (Car) in Pisum sativum L. The pigments were extracted from mature leaves after 12 days of contact with a particular nano-oxide. Vertical bars represent standard deviations (n = 6). Treatments with the same letter are not significantly different according to Tukey’s post hoc test (p = 0.95) (b) appearance of pea leaves from each treatment.
Figure 2. The influence of nanoparticulate CeO2 and ZnO on: (a) photosynthetic pigments: chlorophyll a (Chl a), chlorophyll b (Chl b), and carotenoids (Car) in Pisum sativum L. The pigments were extracted from mature leaves after 12 days of contact with a particular nano-oxide. Vertical bars represent standard deviations (n = 6). Treatments with the same letter are not significantly different according to Tukey’s post hoc test (p = 0.95) (b) appearance of pea leaves from each treatment.
Cells 10 03105 g002
Cells 10 03105 g003 550
Figure 3. The influence of nanoparticulate CeO2 and ZnO on chlorophyll content in Pisum sativum L. expressed in SPAD units. All measurements were performed on mature leaves on the 12th day from administration of the nanoparticles. Vertical bars represent standard deviations (n = 10). Treatments with the same letter are not significantly different according to Tukey’s post hoc test (p = 0.95).
Figure 3. The influence of nanoparticulate CeO2 and ZnO on chlorophyll content in Pisum sativum L. expressed in SPAD units. All measurements were performed on mature leaves on the 12th day from administration of the nanoparticles. Vertical bars represent standard deviations (n = 10). Treatments with the same letter are not significantly different according to Tukey’s post hoc test (p = 0.95).
Cells 10 03105 g003
Cells 10 03105 g004 550
Figure 4. Leaf net photosynthesis A (a), transpiration E (b), stomatal conductance gs (c), sub-stomatal CO2 concentration Ci (d), and water use efficiency (WUE) (e) for Pisum sativum L. grown under the sole or combined CeO2 and ZnO NPs treatments. Concentrations of nanoparticles are given in mg/L of elemental cerium or zinc, respectively. The cultivation time was 12 days. Vertical bars represent standard deviations (n = 6). Distinct letters show the statistically significant differences among treatments as calculated with Tukey’s HSD post hoc test (p = 0.95).
Figure 4. Leaf net photosynthesis A (a), transpiration E (b), stomatal conductance gs (c), sub-stomatal CO2 concentration Ci (d), and water use efficiency (WUE) (e) for Pisum sativum L. grown under the sole or combined CeO2 and ZnO NPs treatments. Concentrations of nanoparticles are given in mg/L of elemental cerium or zinc, respectively. The cultivation time was 12 days. Vertical bars represent standard deviations (n = 6). Distinct letters show the statistically significant differences among treatments as calculated with Tukey’s HSD post hoc test (p = 0.95).
Cells 10 03105 g004
Cells 10 03105 g005 550
Figure 5. Copper (a), manganese (b), iron (c), magnesium (d), calcium (e), and potassium (f) concentrations in roots and shoots of Pisum sativum L. grown under the sole or combined CeO2 and ZnO NPs treatment. Concentrations of nanoparticles are given in mg/L of elemental cerium and zinc, respectively. The cultivation time was 12 days. Vertical bars represent standard deviations (n = 6). Distinct letters show the statistically significant differences among treatments as calculated with Tukey’s HSD post hoc test (p = 0.95).
Figure 5. Copper (a), manganese (b), iron (c), magnesium (d), calcium (e), and potassium (f) concentrations in roots and shoots of Pisum sativum L. grown under the sole or combined CeO2 and ZnO NPs treatment. Concentrations of nanoparticles are given in mg/L of elemental cerium and zinc, respectively. The cultivation time was 12 days. Vertical bars represent standard deviations (n = 6). Distinct letters show the statistically significant differences among treatments as calculated with Tukey’s HSD post hoc test (p = 0.95).
Cells 10 03105 g005
Table
Table 1. Zinc and cerium concentrations in root and shoot of Pisum sativum L. grown under the sole or combined CeO2 and ZnO NPs treatments accompanied by translocation factors (TF). Concentrations of nanoparticles are given in mg/L of elemental cerium or zinc, respectively. The cultivation time was 12 days. Data are the means ± SD (n = 6). Distinct letters show the statistically significant differences among treatments as calculated with Tukey’s HSD post hoc test (p = 0.95). nd: concentration below the detection limit (18 µg/L).
Table 1. Zinc and cerium concentrations in root and shoot of Pisum sativum L. grown under the sole or combined CeO2 and ZnO NPs treatments accompanied by translocation factors (TF). Concentrations of nanoparticles are given in mg/L of elemental cerium or zinc, respectively. The cultivation time was 12 days. Data are the means ± SD (n = 6). Distinct letters show the statistically significant differences among treatments as calculated with Tukey’s HSD post hoc test (p = 0.95). nd: concentration below the detection limit (18 µg/L).
TreatmentZinc Concentration
(mg/kg DW)		TFCerium Concentrations
(mg/kg DW)		TF
RootShootRootShoot
Control97.8 ± 4.5 d61.4 ± 1.1 d0.63ndndnd
Ce 10074.3 ± 5.5 d52.4 ± 2.3 d0.7114,874 ± 495 b110 ± 11 c0.01
Ce 20068.3 ± 6.2 d51.5 ± 2.2 d0.7516,977 ± 1067 a206 ± 14 a0.01
Zn 10025,921 ± 2307 b1160 ± 61 bc0.04ndndnd
Zn 20030,522 ± 2140 a1455 ± 54 a0.05ndndnd
Ce 100 + Zn 10018,192 ± 703 c1079 ± 113 c0.066058 ± 824 d120 ± 7 bc0.02
Ce 200 + Zn 20028,097 ± 3773 ab1236 ± 88 b0.0410,301 ± 1484 c142 ± 10 b0.01
Table
Table 2. Maximum ribulose 1,5-bisphosphate carboxylation rates (Vcmax), maximum electron transport rates (Jmax) and CO2 compensation points determined for Pisum sativum L. plants grown under the sole or combined CeO2 and ZnO NPs treatments. Distinct letters show the statistically significant differences among treatments as calculated with Tukey’s HSD post hoc test (p = 0.95), n = 6.
Table 2. Maximum ribulose 1,5-bisphosphate carboxylation rates (Vcmax), maximum electron transport rates (Jmax) and CO2 compensation points determined for Pisum sativum L. plants grown under the sole or combined CeO2 and ZnO NPs treatments. Distinct letters show the statistically significant differences among treatments as calculated with Tukey’s HSD post hoc test (p = 0.95), n = 6.
TreatmentVcmax
(µmol/m2 s)		Jmax
(µmol/m2 s)		CO2 Compensation Point
(µmol/mol)
Control62.22 ± 1.22 c80.31 ± 0.93 b57.40 ± 1.12 b
Ce 10071.07 ± 1.30 a87.84 ± 0.69 a43.00 ± 0.62 c
Ce 20066.39 ± 0.58 b85.02 ± 1.10 a58.84 ± 1.00 b
Zn 10050.29 ± 1.07 d73.96 ± 1.27 c97.51 ± 0.91 a
Zn 20050.21 ± 0.82 d67.82 ± 1.00 c97.95 ± 1.28 a
Ce 100 + Zn 10060.75 ± 1.41 c79.09 ± 1.01 b96.91 ± 1.34 a
Ce 200 + Zn 20053.81 ± 2.58 d72.78 ± 1.80 c57.39 ± 3.27 b
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Share and Cite

MDPI and ACS Style

Skiba, E.; Pietrzak, M.; Glińska, S.; Wolf, W.M. The Combined Effect of ZnO and CeO2 Nanoparticles on Pisum sativum L.: A Photosynthesis and Nutrients Uptake Study. Cells 2021, 10, 3105. https://doi.org/10.3390/cells10113105

AMA Style

Skiba E, Pietrzak M, Glińska S, Wolf WM. The Combined Effect of ZnO and CeO2 Nanoparticles on Pisum sativum L.: A Photosynthesis and Nutrients Uptake Study. Cells. 2021; 10(11):3105. https://doi.org/10.3390/cells10113105

Chicago/Turabian Style

Skiba, Elżbieta, Monika Pietrzak, Sława Glińska, and Wojciech M. Wolf. 2021. "The Combined Effect of ZnO and CeO2 Nanoparticles on Pisum sativum L.: A Photosynthesis and Nutrients Uptake Study" Cells 10, no. 11: 3105. https://doi.org/10.3390/cells10113105

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop